Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/2/2007
Publication Date: 2/22/2007
Citation: Lin, F., Chen, X. 2007. Genetics and molecular mapping of genes for race-specific all-stage resistance and non-race specific high-temperature adult-plant resistance to stripe rust in spring wheat cultivar Alpowa. Theor. Appl. Genet. 114:1277-1287. Interpretive Summary: Stripe rust is one of the most destructive wheat diseases worldwide. Growing resistant cultivars is the preferred control of the disease. The spring wheat cultivar ‘Alpowa’ has both race-specific, all-stage resistance and non-race specific, high-temperature adult-plant (HTAP) resistance to stripe rust. Genetic and molecular studies were conducted to identify and map genes in Alpowa for the different types of resistance. One single gene was identified for the all-stage resistance and one quantitative trait locus (QTL) with a major effect was identified for the HTAP resistance. The all-stage resistance gene was mapped on the short arm of wheat chromosome 1B and the HTAP resistance gene (QTL) was mapped on the long arm of chromosome 7B. Because the chromosomal location and the race specificity are different from previously reported genes, the all-stage resistance gene is first described in this study and therefore, named YrAlp. The gene for HTAP resistance is different from other resistance genes in the non-race specific nature and the unique chromosomal location, this gene also is newly described and therefore, named Yr39. Both genes are useful in understanding mechanisms of different types of resistance. The Yr39 gene and its tightly linked molecule markers are especially useful in breeding wheat cultivars with durable resistance.
Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars is the preferred control of the disease. The spring wheat cultivar ‘Alpowa’ has both race-specific, all-stage resistance and non-race specific, high-temperature adult-plant (HTAP) resistances to stripe rust. To identify genes for the stripe rust resistances, Alpowa was crossed with ‘Avocet Susceptible’ (AVS). Seedlings of the parents, and F1, F2 and F3 progeny were tested with races PST-1 and PST-21 of P. striiformis f. sp. tritici under controlled greenhouse conditions. Alpowa has a single partially dominant gene, designated as YrAlp, conferring all-stage resistance. Resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrAlp. A linkage group of five RGAP markers and two SSR markers was constructed for YrAlp using 136 F3 lines. Amplification of a set of nulli-tetrasomic Chinese Spring lines with RGAP markers Xwgp47 and Xwgp48 and the two SSR markers indicated that YrAlp is located on the short arm of chromosome 1B. To map quantitative trait loci (QTLs) for the non-race specific HTAP resistance, the parents and 136 F3 lines were tested at two sites near Pullman and one site near Mount Vernon, Washington under naturally infected conditions. A major HTAP QTL was consistently detected across environments and was located on chromosome 7BL. Because of its chromosomal location and the non-race specific nature of the HTAP resistance, this gene is different from previously described genes for adult-plant resistance, and is therefore designated Yr39. The gene contributed to 64.2% of the total variation of relative area under disease progress curve (AUDPC) data and 59.1% of the total variation of infection type data recorded at the heading-flowering stages. Two RGAP markers, Xwgp36 and Xwgp45 with the highest R2 values were closely linked to Yr39, should be useful for incorporation of the non-race specific resistance gene into new cultivars and for combining Yr39 with other genes for durable and high-level resistance.